I don't see a problem with taxing income people make outside of their Social Security paychecks, especially if they are given a $32,000 buffer.
Take my in-laws as an example. They are both retired and held off on drawing their SS benefits until they reach full retirment age. My father-in-law turned 70 this year and began drawing his benefits because he basically had to.
He and my mother-in-law have a handful of rental properties, which provides them a healthy amount of additional income. I'm sure he doesn't necessarily enjoy paying taxes on the income he and my mother-in-law receive from the renters of their properties, but he's never once complained or said he thinks paying taxes on that income is a punishment.
The fact of the matter is that the vast majority of retirees are not making an additional $32,000 a year on top of their Social Security income and I don't really see a problem with individuals or couples paying taxes on the income above that threshold.
My main issue with the Social Security age cap is that people are living longer and longer and therefore receiving their benefits for decades instead of years. The average person didn't even live long enough to benefit from Social Security when it was first passed, but now they are living longer than ever. Add in the fact that Baby Boomers are beginning to draw on their benefits and we have a recipe for disaster if drastic measures aren't made soon.